Defensive publication



cl TWO DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request of the applicant or owner in accordance with the Notice of Apr. 11, 1988, 849 0.6. 1221. Identification is by serial number of the application and the heading indicates the number of pages of specification, including claims, and of sheets of drawing contained in the application as originally died. The tile 0! this application is available to the public for inspection; reproduction may be purchased for 30 cents per sheet.

Applications published under the Defensive Publication Program have not been examined as to the merits of alleged invention. The Patent Oflice makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED APRIL 29, 1969 634,477 PROCESS FOR MULTICOLORED DYEING 0F POLYCARBONAMIDE YARNS AND STAPLE Gordon B. Robbins, Claymont, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Apr. 28, 1967. Published Apr. 29, 1969 Int. Cl. D06p 3/84, 3/24 U.S. Cl. 821 No Drawing. 18 Pages Specification A blend of dissimilar nylon fibers in a carpet are dyed in an aqueous dyebath containing a mixture of acid and basic dyes and a sulfobetaine having the structure:

R-GHr-N-CHzCHgCHz S Orwherein R is an alkyl group of 7 to 17 carbons, m is from 0 to 3, n is from 0 to 3, and the sum of m and n is less than 4 to produce a multicolored carpet. The nylon fiber can have amino ends groups of (a) 55 to 85, (b) 25 to 55, (c) 5 to 25 or (d) 0 to 5 equivalents per 10 grams and can be dyed with acid dyes such as C.I. Acid Yellow 14, Cl. Acid Blue 122, C1. Disperse Blue 7 and Cl. Disperse Yellow 3 while the (d) group nylons can also be dyed by basic dyes such as C.I. Basic Blue 22, and Cl. Basic Blue 21. A mixture of the (a), (b) and (d) nylons are dyed first with the acid dyes and then with the basic dyes noted above. The sulfobetaine prevents the acid and basic dyes from precipitating together. The dyebaths contain, besides a sulfobetaine such as N-tallowor N-coco-N,N-diethanol sulfobetaine, a small amount of silicone anti-foam agent, and sodium phosphate to adjust pH 7.0. The dyeing was done at 98 C. 

